Profile error compensation approaches for parallel nanogrinding of aspherical mould inserts

This paper reports a parallel nanogrinding protocol for fabricating aspherical mould inserts. In the protocol, a preliminary grinding cycle was first employed, which significantly reduced the effect of the initial wheel geometry error on the ground profile accuracy. A new compensation approach was developed. The compensation used the ground profile measured from a Talysurf profilometer to modify the NC toot path for the next grinding cycle. The tool path was modified by offsetting the residual profile error along the normal direction of a grinding point, rather than in the horizontal direction commonly used in the conventional method. The performance of the developed method was evaluated by fabricating aspherical mould inserts on cemented tungsten carbide. The result indicated that the residual profile error after two grinding cycles was reduced to approximately 0.4 mu m in PV, with average surface roughness of below 10 nm, which is more efficient than the conventional compensation process. (C) 2007 Elsevier Ltd. All rights reserved.